Average-Value Modeling of Direct-Driven PMSG-Based Wind Energy Conversion Systems

Control design and stability analysis of direct-driven permanent magnet synchronous generator (PMSG)-based wind energy conversion systems (WECSs) typically involve extensive time-domain simulations and frequency-domain analyses. Those studies rely on accurate and computationally efficient models of WECSs. Detailed switching models can accurately describe the transients of power-electronic converters, but they suffer from low computational efficiency due to the repeated switching events. In this paper, a numerically efficient model is developed for a direct-driven PMSG-based WECS. Analytical and parametric average-value modeling techniques are applied to its switching subsystems, including a 12-pulse diode rectifier, a three-phase-interleaved boost converter, a dual three-phase voltage source inverter (VSI), and a crowbar circuit. The average-value models (AVMs) improve the simulation efficiency by representing the terminal characteristics of switching subsystems with a set of algebraic equations. In addition, numerical linearization techniques can be directly employed for them to obtain frequency-domain characteristics. The proposed model is verified against the detailed switching model and existing AVM in MATLAB/Simulink. It is shown to have excellent accuracy in both time-domain and frequency-domain studies while maintaining high computational efficiency.